It’s remarkable that Stephen Beresford’s first play is being put on in the National’s Lyttelton theatre, which seats 895. Usually playwrights start out in tiny, unglamorous venues. But Beresford’s debut is thoughtful and fresh, delighting in the savagery of a dysfunctional family.

The pivotal figure is Judy Haussman, an ageing hippy portrayed with twinkly conviction by Julie Walters. She’s an eternal teenager, manipulative and flouncy, and at the same time a sturdy matriarch, early on likened to a badger. Nostalgic for the ashrams and exotic pleasures of India, she shares her Devon home with her fierce daughter Libby and surly granddaughter Summer. Their co-existence is emotionally excruciating.

Judy’s son Nick comes to visit. A recovering drug addict, complete with eyeliner and nail varnish, he's a self-confessed acolyte of David Bowie. He has squandered his potential; his literary sensibility has never been fully developed and instead just peeps out here and there in a brilliant, tragic phrase. Also in evidence are the creepily shape-shifting local GP and Daniel, an initially silent pool boy. These six characters are entangled in ways that are sometimes painful and sometimes deliciously comical.

Beresford is interested in the legacy of the Sixties: the sexual frankness, addled offspring, heady idealism and obsession with rebellion. Also at stake is the future of Judy’s eccentric house – a sweeping design by Vicki Mortimer evokes its decay and is packed with lanterns and Tibetan prayer flags. Can Judy cling on to it, maybe even sell it, or will her children take it over and find themselves responsible for its daunting upkeep and its ghosts?

The performances in Howard Davies’s production are impressively detailed. Helen McCrory has a poised rawness as Libby, perpetually strained by having to help shoulder other people’s burdens. Rory Kinnear brings a feverish intelligence to the fidgety, challenging Nick. And Isabella Laughland’s Summer is a well-judged picture of teenage omniscience.

The play itself isn’t perfect. There are moments when it seems contrived, and Daniel appears to be little more than a plot device. But Beresford, previously known as an actor, has a keen ear and is adept at creating scenes full of conflict. His writing drips with smart lines – and pathos, too. By the end The Last of the Haussmans feels like a tribute to Chekhov, mixing spontaneous humour with despair.